Move the rwsem_down_read_failed() function down to below the optimistic spinning section as it is going to use function in that section in a later patch.
Signed-off-by: Waiman Long <[email protected]> --- kernel/locking/rwsem-xadd.c | 96 ++++++++++++++++++++++----------------------- 1 file changed, 48 insertions(+), 48 deletions(-) diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index b5d7055..fb6d6f3 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -219,54 +219,6 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem, } /* - * Wait for the read lock to be granted - */ -__visible -struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) -{ - long count, adjustment = -RWSEM_ACTIVE_READ_BIAS; - struct rwsem_waiter waiter; - DEFINE_WAKE_Q(wake_q); - - waiter.task = current; - waiter.type = RWSEM_WAITING_FOR_READ; - - raw_spin_lock_irq(&sem->wait_lock); - if (list_empty(&sem->wait_list)) - adjustment += RWSEM_WAITING_BIAS; - list_add_tail(&waiter.list, &sem->wait_list); - - /* we're now waiting on the lock, but no longer actively locking */ - count = atomic_long_add_return(adjustment, &sem->count); - - /* - * If there are no active locks, wake the front queued process(es). - * - * If there are no writers and we are first in the queue, - * wake our own waiter to join the existing active readers ! - */ - if (count == RWSEM_WAITING_BIAS || - (count > RWSEM_WAITING_BIAS && - adjustment != -RWSEM_ACTIVE_READ_BIAS)) - __rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q); - - raw_spin_unlock_irq(&sem->wait_lock); - wake_up_q(&wake_q); - - /* wait to be given the lock */ - while (true) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!waiter.task) - break; - schedule(); - } - - __set_current_state(TASK_RUNNING); - return sem; -} -EXPORT_SYMBOL(rwsem_down_read_failed); - -/* * This function must be called with the sem->wait_lock held to prevent * race conditions between checking the rwsem wait list and setting the * sem->count accordingly. @@ -461,6 +413,54 @@ static inline bool rwsem_has_spinner(struct rw_semaphore *sem) #endif /* + * Wait for the read lock to be granted + */ +__visible +struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem) +{ + long count, adjustment = -RWSEM_ACTIVE_READ_BIAS; + struct rwsem_waiter waiter; + DEFINE_WAKE_Q(wake_q); + + waiter.task = current; + waiter.type = RWSEM_WAITING_FOR_READ; + + raw_spin_lock_irq(&sem->wait_lock); + if (list_empty(&sem->wait_list)) + adjustment += RWSEM_WAITING_BIAS; + list_add_tail(&waiter.list, &sem->wait_list); + + /* we're now waiting on the lock, but no longer actively locking */ + count = atomic_long_add_return(adjustment, &sem->count); + + /* + * If there are no active locks, wake the front queued process(es). + * + * If there are no writers and we are first in the queue, + * wake our own waiter to join the existing active readers ! + */ + if (count == RWSEM_WAITING_BIAS || + (count > RWSEM_WAITING_BIAS && + adjustment != -RWSEM_ACTIVE_READ_BIAS)) + __rwsem_mark_wake(sem, RWSEM_WAKE_ANY, &wake_q); + + raw_spin_unlock_irq(&sem->wait_lock); + wake_up_q(&wake_q); + + /* wait to be given the lock */ + while (true) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!waiter.task) + break; + schedule(); + } + + __set_current_state(TASK_RUNNING); + return sem; +} +EXPORT_SYMBOL(rwsem_down_read_failed); + +/* * Wait until we successfully acquire the write lock */ static inline struct rw_semaphore * -- 1.8.3.1
